Aggressive Platy?

I have 3 platys and 3 guppies in my 29-gallon tank and one of the platys (The biggest one) bullies the other 2 platys (He chases them if they come close to him). Would putting that platy in a mesh breeder box help?

I think it's OK. The large male is asserting his dominance, and the others will soon learn to stay away. You have more than enough hiding places so I would let it be as long as the big male doesn't actually injure any fish.